The field of the present invention is that of industrial or household detergency.
Aqueous alkaline solutions containing non-foaming surface agents are commonly used for degreasing hard surfaces, and more specifically for cleaning metal surfaces, floors, walls, tanks, various materials, bodywork, wheel rims or motors in an industrial environment, such as in an institutional environment (hospitals, canteens, restaurants, schools, etc.).
The surfaces agents selected for this purpose are very generally so-called xe2x80x9ccappedxe2x80x9d nonionic surfactants. This refers to compounds having the following structure: a hydrophobic chain of the fatty alkyl or alkylaryl chain type, condensed with ethylene oxide forming a hydrophilic chain, which is itself topped with a hydrophobic group. These compounds are well represented by alcohols with an alkyl or alkylaryl chain containing 8-20 carbon atoms, and preferably 8-12 carbons, condensed with 4-14, preferably 8-10, ethylene oxide molecules, and ending with a hydrophobic group, consisting of an alkyl chain of 3-8 carbon atoms or an alkylaryl chain or a halogen. Such a surface agent is typically represented by xcex1-alkyl-xcfx89-halopoly(oxy-1,2-ethanediyls), such as the compound xcex1-decyl-xcfx89-chloronona(oxyethylene) of formula
CH3xe2x80x94(CH2)9xe2x80x94(Oxe2x80x94CH2xe2x80x94CH2)9xe2x80x94Cl 
Surface agents of this type are sparingly soluble or even entirely insoluble in alkaline solutions, and the alkaline detergent solutions which contain them have a tendency to demix. This phenomenon is overcome by using stabilizers. Stabilizers are well known to those skilled in the art; among these are oxygenated solvents, sodium toluenesulphonate, sodium xylenesulphonate or sodium cumenesulphonate, and alkaline salts of phosphoric esters. They are used in considerable amounts, which can be up to ten parts per part of non-foaming detergent agent. These stabilizers do not participate in the detergency itself, and are the cause of a needless increase in the chemical oxygen demand and the biological oxygen demand (COD-BOD) of the detergent composition waste materials. They can even have the negative effect of giving the composition appreciable foaming power. Consequently, they no longer satisfy the problem of pressurized-jet cleaning.
It has just been found that compositions of the non-foaming detergent/stabilizer/alkenylsuccinic acid or anhydride type constitute bases for producing alkaline cleaning solutions, which are entirely noteworthy as regards their detergent efficacy, their COD/BOD kept within reasonable limits, their stability on storage and their absence of foaming, even under conditions of use with a pressurized jet.
For the purposes of the invention, the non-foaming detergent agent is a compound of formula
R1xe2x80x94(Oxe2x80x94CH2xe2x80x94CH2)nxe2x80x94R2 
in which
R1 is an alkyl chain of 8-20 carbon atoms, and preferably 8-12 carbons, or an octylphenyl or nonylphenly chain, n is from 8 to 15, R2 is an alkoxy radical of 3-5 carbon atoms, a poly(oxyalkylene) radical of formula: 
in which
Rxe2x80x2 is an alkyl radical containing 1 or 2 carbon atoms, p is from 1 to 10, a benzyloxy radical, or chlorine.
These compositions are formed of 25 to 45 parts by weight of the non-foaming detergent agent, 15 to 25 parts by weight of a stabilizer, 30 to 60 parts by weight of alkenylsuccinic acid or anhydride.
The stabilizer is a phosphoric ester of monoester/diester type, obtained by reaction of phosphorus pentoxide with an aliphatic alcohol containing from 4 to 12 carbon atoms; the alkenylsuccinic acid is a compound of formula 
where n is from 4 to 12, and the anhydrides which are the immediate derivatives thereof.
The compositions combining xcex1-decyl-xcfx89-chloro-nona(oxyethylene)
CH3xe2x80x94(CH2)9xe2x80x94(Oxe2x80x94CH2xe2x80x94CH2)9xe2x80x94Cl, 
the xcex1-decyl-xcfx89-benzyloxytrideca(oxyethylene) 
the phosphoric monoester/diester of 2-ethylhexyl, and octenylsuccinic acid, of formula: 
[RN=28805-58-5] or its anhydride are preferred compositions of the invention.
These compositions satisfy the stability/solubility criterion which is defined as follows: they are liquid, clear, stable for at least 60 days over a temperature range of xe2x88x9215xc2x0 C./+40xc2x0 C., and soluble in alkaline solutions.
They can be used to compose detergent washing products containing from 1 to 5 parts by weight of them in an aqueous sodium hydroxide or potassium hydroxide solution, or mixtures of alkali metal salts (sodium and/or potassium phosphates, carbonates or silicates), in which there is no need to introduce hydrotropic agents in order to ensure their homogeneity on storage. Such washing products are also subjects of the invention. These washing products can be used for cleaning hard surfaces, after immediate dilution at room temperature in soft or hard water.